Bài 1:

a,\(0,75+\frac{9}{17}-1\frac{4}{5}-\frac{26}{17}-2\frac{4}{5}\)

\(=\frac{3}{4}+\left(\frac{9}{17}-\frac{26}{17}\right)-\left(1\frac{4}{5}+2\frac{4}{5}\right)\)

\(=\frac{3}{4}-1-\frac{23}{5}\)

\(=\frac{15}{20}-\frac{20}{20}-\frac{92}{20}=\frac{-97}{20}\)

Bài 2:

a, \(\left(2x+\frac{3}{4}\right)-\frac{10}{3}=\frac{-13}{3}\)

\(2x+\frac{3}{4}=\frac{-13}{3}+\frac{10}{3}\)

\(2x+\frac{3}{4}=-1\)

\(2x=-1-\frac{3}{4}\)

\(2x=\frac{-7}{4}\)

x = -7/8

b, 3,2x - 2,7x + 8,5 = 6

x(3,2 - 2,7) = -2,5

0,5x = -2,5

x = -5

a: =35/17-18/17-9/5+4/5

=1-1=0

b: =-7/19(3/17+8/11-1)

=7/19*18/187=126/3553

c: =26/15-11/15-17/3-6/13

=1-6/13-17/3

=7/13-17/3=-200/39

a,\(\frac{4}{5}\)- \(\frac{7}{6}\)+\(\frac{-6}{15}\)

=\(\frac{24}{30}\)-\(\frac{35}{30}\)+\(\frac{-12}{30}\)

=\(\frac{-11}{30}\)+\(\frac{-12}{30}\)=\(\frac{-23}{30}\)

b, \(\frac{-5}{9}\)x \(\frac{7}{13}\)+\(\frac{6}{13}\)x\(\frac{-5}{9}\)+\(\frac{34}{9}\)

= \(\frac{-5}{9}\)x [ \(\frac{7}{13}\)+\(\frac{6}{13}\)] +\(\frac{34}{9}\)

= \(\frac{-5}{9}\)x1 + \(\frac{34}{9}\)

=\(\frac{-5}{9}\)+\(\frac{34}{9}\)

= \(\frac{29}{9}\)

c, \(\frac{51}{8}\) - [\(\frac{35}{8}\)-\(\frac{1}{2}\)]

= \(\frac{51}{8}\)- \(\frac{31}{8}\)

\(\frac{20}{8}\)

d,\(\frac{7}{3}\)x 1,5 - (\(\frac{11}{10}\) + 50%) : \(\frac{4}{5}\)

= \(\frac{7}{3}\)x\(\frac{3}{2}\)- ( \(\frac{11}{10}\)+ \(\frac{1}{2}\)) : \(\frac{4}{5}\)

= \(\frac{7}{2}\)- \(\frac{8}{5}\): \(\frac{4}{5}\)

= \(\frac{7}{2}\)- \(\frac{2}{1}\)

=  \(\frac{7}{2}\) - \(\frac{4}{2}\)

= \(\frac{3}{2}\)

1:

a: =23/27-11/17+4/27+28/17

=23/27+4/27+28/17-11/17

=1+1=2

b: \(=\dfrac{2}{3}\cdot\left(\dfrac{7}{9}+\dfrac{2}{9}\right)-\dfrac{2}{9}\)

=2/3-2/9

=6/9-2/9

=4/9

c: \(=\dfrac{11}{5}\cdot\dfrac{7}{3}-\dfrac{1}{3}\cdot\dfrac{11}{5}\)

=11/5(7/3-1/3)

=11/5*2

=22/5

d: \(=\dfrac{3}{2}\cdot\dfrac{4}{3}\cdot...\cdot\dfrac{2024}{2023}=\dfrac{2024}{2}=1012\)

e: \(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot...\cdot\dfrac{2022}{2023}=\dfrac{1}{2023}\)

`a)3/5+(-4/9)`

`=3/5-4/9`

`=27/45-20/45`

`=7/45`

`b)3/5+2/5 . 15/8`

`=3/5 + 30/40`

`=3/5+3/4`

`=12/20+15/20`

`=27/20`

`c)7/2 . 8/13 + 8/13 . (-5/2)`

`=8/13 . (7/2 +(-5)/2)`

`=8/13 . 1`

`=8/13`

`d)-5/17 . (-9/23)+9/23 . (-22/17) + 11 9/23`

`=-5/17 . (-9/23) + 9/23 . (-1) . 22/17 + 11 + 9/23`

`=-5/17 . (-9/23) + (-9/23) . 22/17+11+9/23`

`= -9/23 ( -5/17 + 22/17)+11+9/23`

`= - 9/23 . 1+11+9/23`

`=-9/23+11+9/23`

`=(-9/23+9/23)+11`

`=0+11`

`=11`

a: =27/45-20/45=7/45

b: =3/5+30/40

=3/5+3/4

=12/20+15/20

=27/20

c: =8/13(7/2-5/2+1)=8/13*2=16/13

d: =9/23*5/17-9/23*22/17+11+9/23

=-9/23+11+9/23

=11

56666666

=7/11+5/6+4/11-1/6

=(7/11+4/11)+(5/6-1/6)

=1+2/3

=5/3

\(A,\dfrac{7}{11}+\dfrac{5}{6}-\dfrac{-4}{11}-\dfrac{1}{6}\)

\(= (\dfrac{7}{11}+\dfrac{-4}{11})-(\dfrac{5}{6}-\dfrac{1}{6})\)

\(=\dfrac{3}{11}-\dfrac{2}{3}\)

\(= \dfrac{9}{33}-\dfrac{22}{33}\)

\(= \dfrac{-13}{33}\)

\(B,\dfrac{5}{9}.\dfrac{7}{3}+\dfrac{5}{9}.\dfrac{9}{13}-\dfrac{5}{9}:\dfrac{13}{5}\)

\(=(\dfrac{5}{9}.\dfrac{5}{9}:\dfrac{5}{9}).\dfrac{7}{3}+\dfrac{9}{13}-\dfrac{13}{5}\)

\(=(\dfrac{5}{9}.\dfrac{7}{3})+(\dfrac{9}{13}-\dfrac{13}{5})\)

\(=(\dfrac{5}{9}.\dfrac{21}{9})+(\dfrac{45}{65}-\dfrac{169}{65})\)

\(=\dfrac{35}{27}+\dfrac{-124}{65}\)

\(=\dfrac{2275}{1755}+\dfrac{-3348}{1755}\)

\(=\dfrac{-1073}{1755}\)

Bài 2 : 

a, \(x=\dfrac{3}{5}-\dfrac{7}{8}=\dfrac{24-30}{40}=-\dfrac{6}{40}=-\dfrac{3}{20}\)

b, \(2x-1=-2\Leftrightarrow x=-\dfrac{1}{2}\)

Cho hình vuông ABCD, M là trung điểm AB. Trên tia đối của tia CB vẽ CN=AM. I là trung điểm MN. Tia DI cắt BC tại E, MN cắt CD tại F. Từ M vẽ MK vuông góc với AB và cắt DE tại K.

a, Cm MKNE là hình thoi (đã làm được)

b, Cm A,I,C thẳng hàng

c, Cho AB=a. Tính diện tích  BMEtheo a (Đã làm được)

Giải Giùm mình đi, nhất là câu b

a) \(\left(5^{17}\div5^{16}\right)\times\left(-2\right)^3\)

\(=5\times\left(-8\right)\)

\(=-40\)

b) \(\left(0,5+15\%\right)\times3\frac{1}{13}\)

\(=\left(\frac{50}{100}+\frac{15}{100}\right)\times\frac{40}{13}\)

\(=\frac{65}{100}\times\frac{40}{13}\)

\(=\frac{10}{5}=2\)

a)  5/17 * 8/-7+8/17*-7/3+-7/3*4/17

-40/119 + 12/17 × -7/3

-40/119 + -28/17 =-236/119

b) -10/13 + 5/17 - 3/13 + 12/17 - 11/20

(5/17+12/17)-(10/13+3/13)-11/20

-11/20

a)  5/17 * 8/-7+8/17*-7/3+-7/3*4/17

-40/119 + 12/17 × -7/3

-40/119 + -28/17 =-236/119

b) -10/13 + 5/17 - 3/13 + 12/17 - 11/20

(5/17+12/17)-(10/13+3/13)-11/20

-11/20